Diaphragm Mitochondrial Alterations in Sepsis

描述(申请人摘要)：最近的研究表明线粒体 功能障碍在脓毒症中起着核心作用，脓毒症是导致死亡和 美国的发病率。导致这一现象的潜在机制 线粒体功能障碍尚不清楚。本提案的目标是 测试脓毒症中自由基生成增加会产生的假设 特定的生化、结构和遗传变化，导致显著的 线粒体功能的生理性改变。我们假设：(A) 脓毒症患者线粒体功能障碍由生理性紊乱所致 Krebs循环酶，复杂的I-IV电子传递链组件，以及 肌酸肌酸激酶，(B)这些生理变化是由于 线粒体蛋白质含量和组成的变化，以及(C) 蛋白质的变化部分是由于自由基介导的细胞内蛋白质的减少。 线粒体基因的转录、表达和翻译。这些假设 将在三组实验中进行测试，使用的是 内毒素引起的脓毒症。目标1的目的是充分描述 脓毒症中线粒体的特殊生理性紊乱；我们将 检测Krebs循环酶活性，评估特定性能 电子传递链中的复合体，评估肌节线粒体 肌酸激酶活性，并进行代谢控制分析。客观化 II将确定线粒体的内容和组成的变化 蛋白质成分(即电子传输链蛋白质亚单位，Krebs 循环酶、肌酸激酶)并比较它们的时间进程 随着生理异常的发展而发生的变化 目标I目标III将评估转录、表达和 线粒体和编码线粒体的核基因的翻译 在目标II中发现耗尽的蛋白质。在所有研究中，我们将 确定自由基在这些脓毒症引起的改变中的作用。 我们的初步数据提供了第一个证据 脓毒症相关线粒体蛋白的氧化修饰和耗竭 复合体I、III和IV中的亚基，NADH生成的显著变化 通过Krebs循环酶，线粒体肌酸激酶的主要减少 活性，以及自由基介导的基因表达的关键变化 脓毒症中的线粒体蛋白。这些数据表明，拟议的 实验应提供重要信息，以了解其发病机制 脓毒症时线粒体功能障碍。

DESCRIPTION (Applicant's abstract): Recent work suggests that mitochondria dysfunction plays a central role in sepsis, a major cause of death and morbidity in the United States. The underlying mechanisms responsible for this mitochondria dysfunction are not known. The goal of the present proposal is to test the hypothesis that increased free radical generation in sepsis produces specific biochemical, structural and genetic changes that result in marked physiologic alterations in mitochondrial function. We postulate: (a) mitochondria dysfunction in sepsis results from physiologic derangements of Krebs cycle enzymes, Complex I-IV electron transport chain components, and sarcomericcreatine kinase, (b) these physiologic changes are due, in turn, to alterations in the content and composition of mitochondrial proteins, and (c) protein changes are due, in part, to free radical-mediated decrements in mitochondrial gene transcription, expression, and translation. These hypotheses will be tested in three groups of experiments, using a model of endotoxin-induced sepsis. The purpose of Objective 1 is to fully characterize the specific physiologic derangements in the mitochondria in sepsis; we will examine Krebs cycle enzyme activities, evaluate specific performance of complexes within the electron transport chain, assess sarcomeric mitochondrial creatine kinase activity, and perform a metabolic control analysis. Objective II will identify changes in the content and composition of mitochondrial protein constituents (i.e. electron transport chain protein subunits, Krebs cycle enzymes, creatine kinase) and compare the time course of these alterations with the development of physiologic abnormalities determined in Objective I. Objective III will evaluate transcription, expression, and translation of mitochondria and nuclear genes encoding for mitochondrial proteins found to be depleted in Objective II. In all studies, we will determine the role of free radical modulation of these sepsis-induced changes. Our preliminary data provide the first evidence of substantial sepsis-associated oxidative modification and depletion of mitochondria protein subunits in Complexes I, III and IV, significant alterations in NADH generation via Krebs cycle enzymes, major decreases in mitochondria creatine kinase activity, and key free radical-mediated changes in gene expression of mitochondrial proteins in sepsis. These data suggest that the proposed experiments should provide important information regarding the pathogenesis of mitochondrial dysfunction in sepsis.